It is recommended that trivalent vaccines for use in the 2017-2018 northern hemisphere influenza season contain the following:

• an A/Michigan/45/2015 (H1N1)pdm09-like virus;
• an A/Hong Kong/4801/2014 (H3N2)-like virus; and
• a B/Brisbane/60/2008-like virus.

It is recommended that quadrivalent vaccines containing two influenza B viruses contain the above three viruses and a B/Phuket/3073/2013-like virus.